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The invention relates to devices for dispensing volatile materials. More specifically, the invention relates to a dispenser that permits the controlled release of volatile materials.
Ether and alcohol-based compounds are commonly used as carriers to distribute air-treating compounds into the atmosphere. For example, when combined with fragrances and/or deodorizing compounds these compounds are useful to reduce or eliminate offensive odors and to provide a long-lasting pleasant odor. When combined with bactericides, insecticides, and insect repellants, for example, these compounds are useful indoors and outdoors in combating unwanted insects and germs. A variety of packages have been used to contain these materials and permit the controlled dispensing of them as vapors into the atmosphere.
It is known in the art to impregnate a solid porous mat with a volatile material, or to place a volatile material in a pan-like metal structure. These mats and pans have been placed on heaters to cause the volatile material to vaporize into the atmosphere. One type of heater used for this purpose was sold by S.C. Johnson and Son, Inc. under the trademark FUYI VAPE. See also U.S. Pat. No. 4,439,415 for a general discussion of heater units used for this purpose. The disclosure of this patent, and of all other publications referred to herein, are incorporated by reference as if fully set forth.
U.S. Pat. No. 6,154,607, commonly owned with this application, also discloses a metal pan having a cavity that accommodates a substrate that is impregnated with a volatile material. The pan is placed on a heater which heats the pan, causing the release of the volatile material. The pan is covered with a permeable membrane that slows the release of the volatile material. However, the permeable member is not easily joined to the metal pan by heat sealing, a preferred, low-cost process that provides a vapor impermeable seal.
U.S. Pat. Nos. 4,145,001 and 5,885,701 describe heat sealed vapor impermeable packages with top and bottom substrates that are heat sealed around the periphery of the package containing the volatile material. The heat seal and the substrates are vapor impermeable. However, these packages are not designed to withstand the high temperatures of heaters and may have unsuitably high vapor-transmission rates. Moreover, the vapor permeable layers of these packages are not readily heat sealable to the metal pans or trays designed for use with such heaters.
Therefore, there is a need for an improved volatile material dispenser.
The invention provides a dispenser with a metallic tray and a vapor permeable lid. The tray contains the volatile material and has an open side with a cast polypropylene face surface. The lid is made of a biaxially oriented polypropylene (OPP) film and is attached to the face surface of the tray so as to cover the open side and permit release of vapors from the volatile material.
In one preferred form, the lid also includes a vapor impermeable outer cover laminate having a layer of polyethylene terephthalate and a foil layer releaseably joined to the OPP film of the lid. The foil layer is preferably adhered to the PET and the OPP by ethylene acrylic acid copolymer.
In another preferred form, the tray includes a bottom and side walls extending up from the perimeter of the bottom to a peripheral lip. After the dispenser is filled with the volatile material, the open end of the tray is preferably heat sealed with the vapor permeable lid and the vapor impermeable cover laminate. The heat sealing is preferably done from above the dispenser so as to limit heat exposure to the volatile. When the volatile material is to be dispensed, the vapor impermeable laminate is peeled back from the dispenser leaving the vapor permeable layer, which maintains the volatile material inside the dispenser and prevents the user from contacting the material while simultaneously permitting the vapor from the volatile material to be released into the surrounding atmosphere.
In another preferred form, the cast polypropylene face surface is joined to the tray by an adhesive laminate. The adhesive laminate includes a colored dye providing a visual indication of the exhaustion of the volatile material. The volatile material is contained within a gel that is transparent (when heated) as is the inner permeable layer of the film, thereby permitting the consumer to see the colored laminate when the dispenser is in use. As the volatile material is used up, the gel turns opaque (white) obscuring the view of the colored laminate and thereby providing a clearly visible end of use indication.
The dispenser may be used independently for dispensing a volatile material or it may be used in conjunction with an electrically-heated vapor-dispensing apparatus.
Other features will become apparent to those skilled in the art from a review of the following detailed description, taken in conjunction with the drawings and the appended claims. While the disclosed dispenser is susceptible of embodiments in various forms, described below are specific embodiments that are intended as illustrative (and not intended to limit the disclosure to the specific embodiments described herein).